Use our ratings of area roofing contractors to find high-quality companies, then get several bids from them. Prices different companies quote for the same work often vary by thousands of dollars. When our undercover shoppers collected prices for reroofing jobs for three typical homes, they were quoted bids ranging from $11,223 to $17,848 for one job, $7,133 to $10,958 for another house, and $13,000 to $15,965 for a third. Don’t assume a low bid signifies lousy work: For each of these three jobs, our shoppers received low prices from top-rated outfits.

Before using any contractor, ask for proof that it is licensed and carries liability and workers’ compensation insurance.

Get a copy of the warranty from the manufacturer of whatever roofing materials are used. Also get a warranty on the roofer’s work—ideally for five years or more—that provides free repairs if your roof leaks.

Get a fixed-price contract that specifies exactly what roof areas are to be covered and other details, such as whether old shingles are to be removed, whether flashings are to be replaced, who is responsible for cleaning up and hauling away debris, and exactly what types and weights of materials are to be used.

Arrange to pay for the work as late in the process as possible. Many contractors allow customers to withhold all payments until the job is complete. Try to arrange to withhold at least a portion of the price until your roof has been tested by stormy weather.